1. Field of the Invention
This invention relates to novel peptide antibiotics and to their use as antimicrobial and antitumor agents. The invention also relates to production of the new peptide antibiotics by fermentation.
2. Description of the Prior Art
U.S. patent application Ser. No. 771,090 filed Aug. 30, 1985, now abandoned, and its continuation-in-part application Ser. No. 855,649 filed Apr. 25, 1986, now U.S. Pat. No. 4,692,510 disclose novel peptide antibiotics of the formula ##STR1## wherein R is CH.sub.3 (CH.sub.2).sub.6 --, CH.sub.3 --(CH.sub.2).sub.4 --CH.dbd.CH(CH.sub.2).sub.2 -- or CH.sub.3 --(CH.sub.2).sub.8 -- which are produced by fermentation by Polyangium brachysporum sp. nov., strain K481-B101 (ATCC 53080). The above-mentioned peptide antibiotics are disclosed as having both antifungal and antitumor activity.